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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Can renewables provide baseload power?

What the science says...

Although renewable energy does not necessarily need to provide baseload power in the short-term, there are several ways in which it can do so. For example, geothermal energy is available at all times, concentrated solar thermal energy has storage capability, and wind energy can be stored in compressed air.

Climate Myth...

Renewables can't provide baseload power

Does Renewable Energy Need to Provide Baseload Power?

A common myth is that because some types of renewable energy do not provide baseload power, they require an equivalent amount of backup power provided by fossil fuel plants. However, this is simply untrue. As wind production fluctuates, it can be supplemented if necessary by a form of baseload power which can start up or whose output can be changed in a relatively short period of time. Hydroelectric and natural gas plants are common choices for this type of reserve power (AWEA 2008). Although a fossil fuel, combustion of natural gas emits only 45% as much carbon dioxide as combustion of coal, and hydroelectric is of course a very low-carbon energy source.

The current energy production structure consists primarily of coal and nuclear energy providing baseload power, while natural gas and hydroelectric power generally provide the variable reserves to meet peak demand. Coal is cheap, dirty, and the plant output cannot be varied easily. It also has high initial investment cost and a long return on investment time. Hydroelectric power is also cheap, clean, and good for both baseload and meeting peak demand, but limited by available natural sources. Natural gas is less dirty than coal, more expensive and used for peak demand. Nuclear power is a low-carbon power source, but with an extremely high investment cost and long return on investment time.

Renewable energy can be used to replace some higher-carbon sources of energy in the power grid and achieve a reduction in total greenhouse gas emissions from power generation, even if not used to provide baseload power. Intermittent renewables can provide 10-20% of our electricity, with hydroelectric and other baseload renewable sources (see below) on top of that. Even if the rapid growth in wind and other intermittent renewable sources continues, it will be over a decade before storage of the intermittent sources becomes a necessity.

Renewable Baseload Energy Sources

Of course in an ideal world, renewable sources would meet all of our energy needs. And there are several means by which renewable energy can indeed provide baseload power.

Concentrated Solar Thermal

One of the more promising renewable energy technologies is concentrated solar thermal, which uses a system of mirrors or lenses to focus solar radiation on a collector. This type of system can collect and store energy in pressurized steam, molten salt, phase change materials, or purified graphite.

The first test of a large-scale thermal solar power tower plant was Solar One in the California Mojave Desert, constructed in 1981. The project produced 10 megawatts (MW) of electricity using 1,818 mirrors, concentrating solar radiation onto a tower which used high-temperature heat transfer fluid to carry the energy to a boiler on the ground, where the steam was used to spin a series of turbines. Water was used as an energy storage medium for Solar One. The system was redesigned in 1995 and renamed Solar Two, which used molten salt as an energy storage medium. In this type of system, molten salt at 290ºC is pumped from a cold storage tank through the receiver where it is heated to about 565ºC. The heated salt then moves on to the hot storage tank (Figure 1). When power is needed from the plant, the hot salt is pumped to a generator that produces steam, which activates a turbine/generator system that creates electricity (NREL 2001).

The Solar Two molten salt system was capable of storing enough energy to produce power three hours after the Sun had set. By using thermal storage, power tower plants can potentially operate for 65 percent of the year without the need for a back-up fuel source. The first commercial concentrated solar thermal plant with molten salt storage - Andasol 1 - was completed in Spain in 2009. Andasol 1 produces 50 MW of power and the molten salt storage can continue to power the plant for approximately 7.5 hours.

Abengoa Solar is building a 280 MW solar thermal plant in Arizona (the Solana Generating Station), scheduled to begin operation in 2013. This plant will also have a molten salt system with up to 6 hours worth of storage. The electrical utility Arizona Public Service has contracted to purchase the power from Solana station for approximately 14 cents per kilawatt-hour.

Italian utility Enel recently unveiled "Archimede", the first concentrated solar thermal plant to use molten salts for both heat storage and heat transfer. Molten salts can operate at higher temperatures than oils, which gives Archimede higher efficiency and power output. With the higher temperature heat storage allowed by the direct use of salts, Archimede can extend its operating hours further than an oil-operated solar thermal plant with molten salt storage. Archimede is a 5 MW plant with 8 hours of storage capacity.

In southern Spain, the Gemasolar plant opened in 2011. It produces 19.9 MW, or approximately 110 gigawatt-hours per year. Gemasolar stores energy in molten salt for up to 15 hours, and is thus able to provide energy 24 hours per day for a minimum of 270 days per year (74% of the year).

The National Renewable Energy Laboratory provides a long list of concentrated solar thermal plants in operation, under construction, and in development, many of which have energy storage systems. In short, solar thermal molten salt power storage is already a reality, and a growing resource.

Geothermal

Geothermal systems extract energy from water exposed to hot rock deep beneath the earth's surface, and thus do not face the intermittency problems of other renewable energy sources like wind and solar. An expert panel concluded that geothermal sources could produce approximately 100 gigawatts (GW) of baseload power to the USA by mid-century, which is approximately 10% of current US generating capacity (MIT 2006). The panel also concluded that a research and development investment of less than $1 billion would make geothermal energy economically viable.

The MIT-led report focuses on a technology called enhanced or engineered geothermal systems (EGS), which doesn't require ideal subsurface conditions and could theoretically work anywhere. installing an EGS plant typically involves drilling a 10- to 12-inch-wide, three- to four-kilometer-deep hole, expanding existing fractures in the rock at the bottom of the hole by pumping down water under high pressure, and drilling a second hole into those fractures. Water pumped down one hole courses through the gaps in the rock, heats up, and flows back to the surface through the second hole. Finally, a plant harvests the heat and circulates the cooled water back down into the cracks (MIT 2007).

Currently there are 10.7 GW of geothermal power online globally, with a 20% increase in geothermal power online capacity since 2005. The USA leads the world in geothermal production with 3.1 GW of installed capacity from 77 power plants (GEA 2010).

Wind Compressed Air Energy Storage (CAES)

Various methods of storing wind energy have been explored, including pumped hydroelectric storage, batteries, superconducting magnets, flywheels, regenerative fuel cells, and CAES. CAES has been identified as the most promising technology for utility-scale bulk wind energy storage due to relatively low costs, environmental impacts, and high reliability (Cavallo 2005). CAES plants are currently operational in Huntorf, Germany (290 MW, since 1978) and Macintosh, Alabama (110 MW, since 1991). Recently this type of system has been considered to solve the intermittency difficulties associated with wind turbines. It is estimated that more than 80% of the U.S. territory has geology suitable for such underground storage (Gardner and Haynes 2007).

The Iowa Stored Energy Park has been proposed to store air in an underground geologic structure during time periods of low customer electric demand and high wind. The project is hoping to store a 20 week supply of compressed air and have approximately 270 MW of generating capacity. The project is anticipated to be operational in 2015.

A similar system has been proposed to create a wind turbine-air compressor. Instead of generating electricity, each wind turbine will pump air into CAES. This approach has the potential for saving money and improving overall efficiency by eliminating the intermediate and unnecessary electrical generation between the turbine and the air compressor (Gardner and Haynes 2007).

Pumped Heat Energy Storage

Another promising energy storage technology involves pumping heat between tanks containing hot and cold insulated gravel. Electrical power is input to the system, which compresses/expands air to approximately 500°C on the hot side and -150°C on the cold side. The air is passed through the two piles of gravel where it gives up its heat/cold to the gravel. In order to regenerate the electricity, the cycle is simply reversed. The benefits of this type of system are that it would take up relatively little space, the round-trip efficiency is approximately 75%, and gravel is a very cheap and abundant material.

Spent Electric Vehicle (EV) Battery Storage

As plug-in hybrids and electric vehicles become more commonplace, the possibility exists to utilize the spent EV batteries for power grid storage after their automotive life, at which point they will still have significant storage capacity. General Motors has been examining this possibility, for example. If a sufficiently large number of former EV batteries could be hooked up to the power grid, they could provide storage capacity for intermittent renewable energy sources.

100% Energy from Renewables Studies

A few studies have put forth plans detailing exactly how we can meet 100% of global energy needs from renewable sources.

In Part I of their study, J&D examine the technologies, energy resources, infrastructure, and materials necessary to provide all energy from WWS sources. In Part II of the study, J&D examine the variability of WWS energy, and the costs of their proposal. J&D project that when accounting for the costs associated with air pollution and climate change, all the WWS technologies they consider will be cheaper than conventional energy sources (including coal) by 2020 or 2030, and in fact onshore wind is already cheaper.

Summary

To sum up, there are several types of renewable energy which can provide baseload power. It will be over a decade before we can produce sufficient intermittent renewable energy to require high levels of storage, and there are several promising energy storage technologies. One study found that the UK power grid could accommodate approximately 10-20% of energy from intermittent renewable sources without a "significant issue" (Carbon Trust and DTI 2003). By the time renewable energy sources begin to displace a significant part of hydrocarbon generation, there may even be new storage technologies coming into play. The US Department of Energy has made large-scale energy storage one if its research priorities, recently awarding $24.7 million in research grants for Grid-Scale Rampable Intermittent Dispatchable Storage. And several plans have been put forth to meet 100% of global energy needs from renewable sources by 2050.

Comments

I believe the answer to utility scale electricity storage is at http://www.launchpnt.com/portfolio/grid-scale-electricity-storage.html
Pumped Hydro Storage is generally accepted as the best way of storing electricity. The problem is you need a mountain and mountains are usually (and quite rightly) stoutly defended by the environmental lobby.
Gravity Power ticks all the pumped storage boxes PLUS it can be sited almost anywhere with minimal environmental issues.
It can store GW scale power over hours or even days if necessary and at a fraction of the cost of traditional PHS.
It can be used as load follower or peaking plant and it can mitigate for the variability of wind and solar.

One place where baseload power can be provided by wind, is a chain of wind turbines running along the Atlantic coast of the northern U.S. The Atlantic Wind Connection project will take advantage of wind patterns that blow sufficiently at least somewhere along that chain at all times.

Is there a thread that discusses the potential for systems that are already well-established to be a part of a carbon-neutral power grid. Examples would be nuclear power fossil fuels with Carbon Capture and Sequestration?

The problem with renewables - except for hydro - is that they cannot provide peak load either.

Hydro, in the form of pumped storage, is used where possible right now, it is not likely to be expandable to meet the difficult volatility problems arising from wind, wave and solar renewables and the slightly more tractable tidal variability.

Response: [muoncounter] Before we get going with multiple-hundreds of comments, please note that unsubstantiated claims have little or no value. Your statement about pumped storage not likely to be expandable falls into that category.

damorbel, the only problem with renewables not being able to "provide peak load either" is grid construction and design.

The issue is not variability, it's having enough of solar or wind and their associated storage in enough places with good enough connections to other places that might be running short at a particular time. With tidal, run of river and geothermal as a basis for predictable supply - once again depending on the grid - the variable elements may also have to come from outside a particular area. Seeing as centralised generation often serves long distances, that isn't the issue. It's only the grid being able to accept from as well as distribute to many distant places at a time.

Remember also that sophisticated heating, cooling and refrigeration systems can be remotely adjusted, varying demand if needed. And in a decade or so, a good (and growing) proportion of electric cars will have a nice neat storage system always available.

All we have to do is stop thinking that power (and storage) must always come from a central point.

"The issue is not variability, it's having enough of solar or wind and their associated storage in enough places with good enough connections to other places that might be running short at a particular time."

I do not follow your argument. Surely it is the variability of most renewables that gives rise to the need for "enough connections" to "their associated storage" in the first place.

I agree that "It's only the grid being able to accept from as well as distribute to many distant places at a time." But I don't see that as a problem.

Grids can as easily source or sink energy as required, that is the essence of the Cross Channel Link - France has a different peak time to England thus it is easy to use one set of generators to assist with the peak load of a neighbouring one.

However the assistance can be planned because the peaks are known (approximately); the matter becomes much more hazardous with renewable troughs that are not predictable. Worse still, the troughs in wind power can extend for weeks, far beyond any economic strorage facility to fill - storage in any form is very expensive.

Okay so to better understand my opinion, I'm a big free market guy, believe the market is self-correcting and finds its own solutions. When I look at global final energy consumption and I see alternatives contributing between 0-1%, I'm not optomistic. I firmly believe there would be a car running on solar if it were cheaper but I don't think it is. I think we might find that fossil fuels are permanently cheaper than alternatives because of the massive potential in gas hydrates.

Response:

[dana1981] My moped runs on solar energy. A lot of peoples' cars run on solar energy, too. I'll be one of them in a few years. Fossil fuels are already more costly than renewable energy, and that includes coal. Try reading the Renewable energy is too expensive rebuttal. Right now the "free market" doesn't take into account the full costs of fossil fuel energy. Not even close. Economists hate it - it's a market failure. That's the point of a carbon price, to make the free market work better.

rcglinski, did you actually read the report that the graph came from ? In it, it states this :

In 2050, energy demand is 15 per cent lower than in 2005. Although population, industrial output, passenger travel and freight transport continue to rise as predicted, ambitious energy-saving measures allow us to do more with less. Industry uses more recycled and energy-efficient materials, buildings are constructed or upgraded to need minimal energy for heating and cooling, and there is a shift to more efficient forms of transport.

Now, straight-faced or otherwise, what are your arguments against that ?

Sasquatch - As I stated on the earlier thread, renewables can be reliable sources of baseload power.

The big misperception that I see is that most people look at renewable power units (single sites), rather than systems. Archer & Jacobson 2007, as I pointed you to earlier, examined wind systems with 19-20 sites, and found that 33-47% of the average output was reliable as baseload power by current availability standards. Extending that, an overbuild of 2.5-3x capacity would be required to provide baseload, with the remainder perhaps available for biofuels, direct CO2->liquid fuel production (net carbon impact of zero), desalination, or other more intermittent uses.

Solar, in particular solar thermal, offers the possibility of multiple day backups at individual units with molten salt or other heat storage mechanisms - increasing unit up-time, and adding those benefits to the system support shown in the wind study.

The reason a system becomes an order of magnitude more dependable than individual units is because a reasonably sized system extends over more than a single weather pattern - meaning the entire network can't be downed by a single cloudy low pressure system or locally dead air.

I would be interested in your reactions to the Archer & Jacobson paper - if you have a chance to read it, please comment on this (on-topic) thread.

Solar PV power, incidentally, is on a Moore's Law cost curve, and should soon be cheaper than coal on a per kW basis - even without externalized costs of coal burning accounted for. The same goes for wind power as production ramps up. And renewables are currently the fastest growing sector of power production: solar alone is estimated to provide 50% of the worlds electricity within 50 years - we could likely do it faster if we tried.

In the "advanced" version of the text, you quote an European Renewable Energy Council (EREC)'s study. But EREC is an industrial lobby, as it is specified on their webite : "The European Renewable Energy Council (EREC) came into existence in the year 2000, as the voice of the European renewable energy industry." You should inform your reader that there is conflict of interest in this case, because the 'EREC' denomination could suggest it is an independent or academic committee.

More broadly, it is better to rely on IPCC report : SRREN 2011. First, informations are updated. Second, anyone familiar with energy literature knows that are lot of "scenarios" in publications, but to qualify them as "plausible" as you did for some is a value judgement quite difficult to found. If you look at the figure 9 of the SRREN SPM, you can see the best estimates of Global RE primary energy supply from 164 scenarios. This is a more clear, more large and so more robust information than selective case studies (and this is why, of course, IPCC reports are precious).

The report states : "In scenarios that stabilize the atmospheric CO2 concentrations at a level of less than 440 ppm, the median RE deployment level in 2050 is 248 EJ/yr (139 in 2030), with the highest levels reaching 428 EJ/yr by 2050 (252 in 2030)." (Note that he most optimistic scenario is co-produced by Greenpeace and EREC, previously mentioned, but some other scenarios used in this report are funded by fossil industry, not all scenario are from academic sources). The inter-quartile range (25th to 75th percentile) of the RE supply in this most optimistic scenarios for climate mitigation (450 ppm target) is 180-320 EJ/y in 2050.

Current primary energy production for 7 billon humans is 492 EJ (same source, year 2008). It has doubled from 1972 to 2008, as it can be observed in IEA key stats 2010 and it is expected to grow with demography and socio-economic development in emerging countries. Estimated population for 2050 is 8-10,5 billion persons according to the latest UN Population Division projection. The median-variant scenario, supposed to be the more likely, is 9,2 billion persons in 2050, a growth of 20% from now.

So, the conclusion from IPCC SRREN 2011 report is that, for a large majority of energy scenarios, it is unlikely RE will be sufficient to cover all the energy supply/demand in 2050. Beside residual fossil use in the energy mix, these scenarios usually include nuclear and CCS (carbon capture and storage) so as to meet the 450 ppm target. They also rely on various assumptions on energy intensity gain in the coming decades so as to reduce the baseload demand (your first point on efficiency).

These conclusions will of course evolve in coming years. As SRREN note : Enhanced scientiﬁc and engineering knowledge should lead to performance improvements and cost reductions in RE technologies. Additional knowledge related to RE and its role in GHG emissions reductions remains to be gained in a number of broad areas including:
• Future cost and timing of RE deployment;
• Realizable technical potential for RE at all geographical scales;
• Technical and institutional challenges and costs of integrating diverse RE technologies into energy systems and markets;
• Comprehensive assessments of socioeconomic and environmental aspects of RE and other energy technologies;
• Opportunities for meeting the needs of developing countries with sustainable RE services; and
• Policy, institutional and ﬁnancial mechanisms to enable cost-effective deployment of RE in a wide variety of contexts.
Knowledge about RE and its climate change mitigation potential continues to advance

It must be finally noted that expected RE penetration doesn't imply necessarily all costs will decrease, as SRREN recalls : "As the penetration of variable RE sources increases, maintaining system reliability may become more challenging and costly. Having a portfolio of complementary RE technologies is one solution to reduce the risks and costs of RE integration. Other solutions include the development of complementary ﬂ exible generation and the more ﬂexible operation of existing schemes; improved short-term forecasting, system operation and planning tools; electricity demand that can respond in relation to supply availability; energy storage technologies (including storage-based hydropower); and modiﬁ ed institutional arrangements. Electricity network transmission (including interconnections between systems) and/or distribution infrastructure may need to be strengthened and extended, partly because of the geographical distribution and ﬁxed remote locations of many RE resources." As KR noted in #12, units are not systems, so the decarbonization of energy doesn't solely consist to add RE units.

skept.fr @16, I am having difficulty accepting the genuineness of your criticisms, which seem to be nitpicking and inconsistent:

1) Regarding EREC, that it is an industry body is clearly identified on the second page of the report linked above, so there is no concealment. Nor does it follow from the fact that it is an industry body that their scenario is unrealistic. If you have any specific criticisms of that report, and others relied on in the advanced article, you should make them.

2) Your preference for relying on the IPCC seems very inconsistent, and evaporates when doing so does not support your position (as I have shown on a previous thread). As a case in point, you quote the SSREN 2011 report as saying:

"In scenarios that stabilize the atmospheric CO2 concentrations at a level of less than 440 ppm, the median RE deployment level in 2050 is 248 EJ/yr (139 in 2030), with the highest levels reaching 428 EJ/yr by 2050 (252 in 2030)."

(My emphasis)

The clear import of these words is that scenarios in which Renewable Energy only constitutes 248 EJ/yr can meet a target of 440 ppmv (ie, inside the 450 ppmv guard rail). Yet you have quoted these figures from this report as proof that the 450 ppmv target cannot be met.

If you wish to rely on the IPCC, then rely on the IPCC. Given your repeated mantra that we should only rely on the IPCC, your selective reliance shows you are pushing an agenda.

3) It is also noteworthy that you pick out as worthy of mention that the Advanced REvolution scenario was co-produced by EREC and greenpeace. In the first instance, that is incorrect. It was sponsored by Greenpeace and EREC, but it was produced by a number of scholars two of whom where employed by Greenpeace, but the rest of whom where academics. In the second instance you neglect the obvious point that it was accepted as a plausible scenario by the IPCC, including a panel with more members with commercial ties to the fossil fuel industry than those with ties to RE bodies, or activist organizations. In the third instance you neglect the fact that it was independently published in a peer reviewed journal.

Your attempt to poison the water against this scenario is a further example of your inconsistency in reliance on the IPCC, which only appears when deployable as a rhetorical device in your arguments.

4) It is a simple fact that all existing power plants will exceed their current design life by 2060 at the latest, and most well before that. It is also a fact that renewable energy can currently supply energy at a cost that is only 2 to 3 times current costs using fossil fuels at most, and arguably current designs cost significantly less. Given that energy use represents a very small part of total GDP, and given the very large expenditures in our society on frivolities, there is no doubt that we have the technical capacity to meet nearly all our energy needs with RE by 2050 by the simple expedient of replacing obsolete plants with RE plants as the reach their designed age limit, and by ensuring all new plants are RE plants.

1) SkS Comments Policy indicates : 'You may criticise a person's methods but not their motives' So please, stick on that and stop with insulting metaphor like "Your attempt to poison the water". My point above was informative and IPCC-based. I don't want to lose time with endless over-interpretations of each of my word here.

2) You call "pick out" some informations that have been widely discussed, notably in Nature Climate Change. So I suppose my "pick out" is nor more that information for readers from the science news on climate. Every one can read here and here this debate about the SRREN 2011. Of course [r]Evolution is eligible to SRREN (it has been!) as are the fossil-funded scenario I mention on my comment. And in a previous comment in the WEO2011 discussion, I speak of Dr Teske as a scientist and lead author of SRREN 2011 (that is of course compatible with the fact that the [r]–Evolution model Dr Teske manages is an order from EREC-Greenpeace).

3) As far I remember, I've quoted these data in the IEA WEO2011 discussion not for "proving" the 450 target cannot be sustained (our point). Here is what I actually said : Unless you cherrypick optimistic models (exactly as some persons cherrypick optimistic CO2 sensitivity, but they are not serious for that reason), you have a higher probability of modest contribution of RE in the future energy mix : about 50% of the primary energy we consume now, but in 2050 there will be 9 billions humans to feed, heat, educate, etc. and we hope in better conditions than now. Most of these models depend on nuclear, biofuel, CCS coal, etc. Another strawman from you : I said exactly what I say here, quite in different terms, 248 EJ/y from RE is half our current production, most scenarios rely on nuclear, CCS, etc.

4) "What is lacking is not the ability but the political will" You can perfectly defend this personal and general interpretation, that was not my point. I just give some results from SRREN 2011, informative for anyone is interested in the energy conditions of climate mitigation.

Response:

[DB] "stop with insulting metaphor like "Your attempt to poison the water""

In the future, please better adhere to the Comments Policy yourself rather than attempting to use it to chastise others. And sticking to facts and citable sources from the peer-reviewed literature will better support your position instead of snark and sarcasm.

1) Reference to "poisoning the water" or "poisoning the wells" is reference to a rhetorical tactic, and hence is a comment on your methods, not your motives. What is more, as you apply similar (and inaccurate) methodological claims about myself (see your point 3), and have directly questioned other commentors motives in other threads, your challenge here is hypocritical to say the least.

2) The [r]Evolution scenario was widely, and unjustifiably, attacked based on its authorship at the time of release of the SSREN report for political reasons. I have extensively argued against that attack both here and on the blog of Mark Lynas, the author the Nature Climate Change article to which you refer. Applying Lynas' implicit standard that employees of, and papers commissioned by, advocacy groups should automatically be excluded IPCC processes is unsustainable both because it excludes some work of genuine quality, and because a similar standard is not applied (and could not be applied) to industry groups, notably fossil fuel industry groups.

3) You said in the Farenheight 451 thread:

"[KR] I think renewable energy development can be a definite win-win scenario

[skept.fr] I already gave above the numbers from IPCC SRREN 2011 concerning real capacities of RE in 2050 according to the median estimate of energy-economy scenarios. So you have to be specific : in a 450 ppm target in 2050, RE are planned to likely produce something like 250EJ/y, half of what we need now for 7 billion (500 EJ), not to say what we will need tomorrow for 9 billion."

The context of that discussion was your challenge to the pausibility of achieving a 450 ppmv target, which you then when on to so sarcastically describe.

I note that the various SSREN scenarios all allow for an increasing population and ongoing third world development. As the entire basis of your argument against a 450 ppmv target is that it is incompatible with population growth and third world development. Given that you purport that we should accept the IPCC conclusions (at least whenever they agree with you), then we ought also to accept the conclusion that a 450 ppmv target is consistent with ongoing population growth and third world development.

There is therefore, no straw man here of my construction. I see that you have been picking a lot of cherries, however.

We must first precise that is not an ‘ideal’, but a necessity. No civilization can be founded on non renewable resources like fossil fuels, and it is extremely likely the actual 80% fossil world energy mix would lead us to an energy, climate and economy collapse during this century.

Even for a layperson blind to deleterious climate change, the dependency of our economy and society to fossil fuel is to be viewed as a highly risky bet. There is no consensus between experts on the total amount of recoverable quantities of fossil sources (eg Höök 2010, Chiari 2011) and some analysts (for example Lipson 2011) even suggest our current recession is partly due to a too high depedency to fossil energy sources (notably already-depleted conventional oil) and their high volatility prices (also of interest Jin and Fan 2011 on commodity effect, Chen 2010 on bear market trend, etc.). All that is subject to debate among specialists (see Segal 2011 for an example of counter-interpretation), but it would be at least unreasonable to plan the long term development of humanity and welfare of future generations on such a fragile socle.

For a more precise example, as SkS mentioned the gas as a possible and less pollutant than coal part of baseload power during the coming transition, in a recent estimate of gas ultimately recoverable resource ( Mohr et Evans 2011) comparing six scenarios with different assumptions, gas production should peak between 2025 and 2066 at 140–217 EJ/y. As a production peak implies an exploding market price, with deleterious effect on economy and society, and as energy transition are decades-long challenge, we can rely partly on gas for the first part of the century but our energy targets for 2050 and beyond should by no way include gas as an inexhaustible resource it is not.

Of course, when present and projected climate externalities of fossil use are integrated, the probability of collapse (at least sustained recession and associated problems) is even higher because part of our precious but rare energy will be devoted to costly adaptations to climate change, rather than to productive activities.

So, the ‘precautionary principle’ as well as the physical limits of resources indicate that a renewable-based energy mix will be a necessity for this century, not jus an ideal.

One of the SRREN 2011 robust conclusions is that even for scenarios without ambitious climate targets, the part of RE in the primary energy supply is planned to increase in coming decades for all models. And of course, the more ambitious our climate targets, the more fastly RE will penetrate the energy system. I think there is no reasonable objection to these basic facts.

As most REs have lower known externalities than fossil or nuclear sources, and as they can supply the long term goals necessary to all human society, the only objections to a large deployment we can meet in literature is either the relative cost (economical objection) or the large-scale feasibility (technical objection). The point of this SkS article is the second family of objections, and I’ll make some further observations about each RE.

skept.fr @20, I welcome the return of the fact based focus which have made your posts such enjoyable reads for me, with the exception of certain recent departures.

I appreciate your excellent summary of the situation. I find little to disagree with, and nothing fundamental.

My only quibble is with your claim that peak production of gas inevitably means "exploding market prices". Price increases are effectively limited by the price of the nearest effective substitute. For gas this may be supposed to be some combination of renewable energy on the assumption that, renewable energy in 2050 will be cheaper in real terms per kilowatthour than currently, and that in 2050, carbon prices will make coal too expensive. In that circumstance, rising prices associated with peak production will just drive energy supply across to renewable (or nuclear) energy. If Renewable Energy is already cheaper than gas per kilowatthour, there may well be no price increase with peak production, but only a retreat into specialist uses such as the Haber-Bosch process in which gas retains a competitive advantage.

#21 Tom : I agree of course with your point. I was probably not clear because I mentioned SkS reference to gas, but my point was related to peak risk in the hypothesis of a business as usual scenario – in fact, what we do for the moment. If a peak (oil, gas or coal) occurs when you haven't already and seriously engaged your energy transition toward other sources, and so limited your dependency to the peaking source, you will have major problems to develop rapidly substitutes because the economic effect of the unprepared peak will seriously damage your existing infrastructure and your economic capacity to invest. Such a short-termism is unfortunately the way we choose for the moment, we are blind to energy as to climate risks. I think we hope that the market prices correctly reflect the value of an energy source at all timescale. IMO, it doesn't. Not only market prices ignore the long-term externalities from climate, but they also ignore the real geologic quantities of carbon sources (asymmetry of information) and the time/effort needed by a human society to engage an energy transition (moral hazard, unrealistic discount rate). Market prices, at least in their current condition of emergence, are the produces of such short-term and poor-informed anticipation that they are not pertinent for climate and energy policy choices. But I'll not deepen these points here, as the real subject of the SkS article is the technological level of RE alternative to fossil energy.

Not much time right now, but I continue with some general views from the SRREN 2011.

First, orders of magnitude. Readers must recall that we currently produce 492 EJ/y, but with 197 EJ/y losses in production, transportation and conversion of energy, so we actually consume 294 EJ/y.

On this table, IPCC authors give the technical potential of RE, minimum and maximum, as estimated by literature. Technical potential is what we could produce from renewable sources (wind, sun, ocean, geothermia, biomass) with current technology.

So, the good new is that even the minimum estimates of RE potential total as high as approx 1900 EJ/y, that is nearly five times what we produce now (at 80% from fossil). As this estimate results from actual knowledges and devices: it is not an optimistic projection of what we could do in an hypothetical future with an hypothetical progress, but an assessment of what we could do now.

This figure helps to see where the biggest potentials are and are not. For example, hydropower estimate are convergent but low, 50 EJ /y for minimum and 52 EJ/y for maximum. So, we should not rely to hydro as a baseload power, because it too low for our needs, except in some very well endowed countries like Norway (99% of electricity production from hydro).

Wind and mostly solar have the highest potential for producing electricity and heat. I’ll try to adress later these two energy sources. Production of primary energy or electricity is one thing, but the real challenge is of course to satisfy our final uses in society, so to transport, store, convert this energy.

This article from Bloomburg says solar power is now cheaper than diesel in India. Many companies have diesel generators because the power grid cannot keep up with peak demand and they have rolling blackouts. Solar is being installed primarily because it is cheaper. It also generates during the day when blackouts are more common. Solar only became cheaper than diesel last year. Coal is still considerably cheaper than solar but solar is easy for small users to install. Companies install solar on the roofs of buildings.

The projected energy consumption, the dotted line, appears too low. The population from 2000 to 2050 is to grow from 6 bil to about 10 bil. However the middle classing of India and china will be a large energy demand increase.

There is not enough focus on hydro. Hydro can produce large amounts of electricity on any day you choose, but not every day as the water will run out. As a backup for wind or solar PV, when it has been cloudy for days and the storages are depleted, or there has been unusually light winds over large areas, the hydro can reliably fill the gap. It is the only large scale energy storage system that is currently commercialized, and has been for decades.

Hydro can provide reliable cheap power but this is very dependent on site. In NZ, there are very few large scale sites left, even fewer cheap ones. I imagine the situation is similar in many other countries. You need large reliable water volume (easy) and substantial fall (tough) on a site with cheap construction.

For energy storage water is pumped from a low level dam to a high level dam when there is excess power, say with solar PV during the day, and then used to generate power in the evening by running the water back to the low level dam.

Of course the measure for all energy storage systems is what percentage of the energy do you get back, and what are losses during holding. Hydro has very low holding lossess. You can store it for 12 months and only lose a little to evaporation and seepage.

My local paper had an article on financing a nuclear power plant. It is only possible because the local ratepayers must pay 10 years in advance of receiving the power and the power company makes 15% even if the plant is never built. They stand to profit $150 million now and they have not even applied for a permit to build yet. If that is the only way to finance nuclear it is not economic.

A&J stated that coal fired power had an availability of 87.5% and compared
this with the availability that a wind power network of 19 interconnected
sites spread across midwest USA can achieve. The comparison benchmark for availability for wind to achieve in the report became 87.5%.

The critical flaw in the argument is that 87.5% is the availability of a single
coal fired generator, it is not the availability of a coal fired power
network!!

So they are comparing a wind network with a single coal fired generator.

How something like that passed peer review is astounding. If you still have any
doubt that 87.5% availabilty is incorrect, well this would mean householders
supplied by coal power would have blackouts for 1095 hours per year (12.5% x
365.25 days x 24 hours)

Those households who have coal fired power would typically have blackouts
less than 8 hrs per year, thats 99.9% availabilty, because the coal fired
units are also interconnected and they have excess generators running at any time to pick up the load if one generator trips.

If you refer to the A&J chart of "Generation duration curves for arrays",
for 99.9% availability and 19 sites this means the available power per
generator is about 30 kW, it does not give the about 250kW that 87.5% would
imply. A significant difference!!

I read the article you linked, but you really shouldnt blame the nuclear power company, you should blame the legislators you voted for that signed the contract you consider bad.

Having said that, it is not uncommon for governments to make contributions to all sorts of large projects, because without a contribution the project may not be viable without charging more for their product, and most governments try to keep utility prices down.

Realist,
Who made the bad deal is not the question. Big energy has political friends, is this a surprise? The point is that if nuclear power plants require this type of financing they are not economic. This project is likely to be stopped in the near future, it is not economic and people are starting to get angry about high prices for energy we will never receive.

Michael Sweet
No its not a surprise that the governments have political friends, but someone must have voted for these guys who signed the bad contract?

Virtually all electicity infrastructure is subsidised somehow, not just nuclear. Wind and solar presently get very high subsidies in many parts of the world and probably in Florida too.

Comparing subsidies on the basis of MW.hr per year generated (not installed eg include availability), then hundreds of millions dollars for what is probably a 1000 MW plant is much lower than wbhat I have seen as typical wind and solar subsidies eg in Germany and in Australia.

"Virtually all electicity infrastructure is subsidised somehow, not just nuclear"

And that applies to hydro, coal and natural gas as well. Yet the companies running it do so as if it was entirely their own and the taxpayers who made them possible in the first place have a say in prices that amounts to, what exactly?

Wind and solar need and deserve subsidies, their renewable character alone earns them that. Coal, oil and gas get subsidies based on what premise? That they're too expensive to be set up by a purely private venture? That they'll have a hard time to make profits?

And then they're run as if they were private once built. Please. The belly aching about subsidies is just the weakest argument one can possibly make in this debate. I'll pay attention to that argument once all subsidies for oil, coal and gas are killed. Politics being what they are, that's not happening any time soon.

Yes people voted for the guys who signed the contracts, after having their minds thoroughly manipulated by, guess what, private companies that specialize in mind manipulation. And considering the citical thinking abilities and Dunning-Kruger effect we get to see at work just on this site, these companies have their work cut out for them. The representative republic principles met their limits long ago, as human duplicity knows no bound. Now the circus has taken over. Enjoy.

@33
Interesting how of the nine lines I wrote you only responded on one.

You asked on what premise electricity infrastructure is subsidised? The answer was in my previous post:-

"Having said that, it is not uncommon for governments to make contributions to all sorts of large projects, because without a contribution the project may not be viable without charging more for their product, and most governments try to keep utility prices down."

You need to consider subsidies in conjunction with the royalties. With oil gas and coal the subsidies are insignificant compared to the royalties and taxes paid. Governments know that any subsidy paid they will get back many times over.

Of course the companies run it as if it was private even if they received a subsidy, the same way someone who gets a first home buyers grant considers the house is their own and not the governments. Thats just a red herring.

"Private companies that specialise in mind manipulation" Huh? Could you please back up your claim with the names of some of these companies?

#35: How does "without a contribution the project may not be viable without charging more for their product, and most governments try to keep utility prices down" square with some of the largest corporate profits on the planet. It's not as if Exxon is going to go bust even if it reduced it's profits by the GDP of several small African countries...

@36
Well Exxon doesnt build power stations so your post is not related to the conversation at the time of my comment.

But if you want to complain about resource company profits then blame legislators who haven't negotiated sufficient royalties, and ahem, the voters who put them there!

Remember petroleum royalties are an absolute cash cow for many governments and keep some countries afloat. So a transition to renewables will need alternative income sources for many governments and countries, which to date has not been widely discussed.

#38
No I don't think there will be royalties on most non-ff energy sources. I don't think for instance that there will be a royalty to the government for wind or solar, perhaps something like geothermal might if there is a prime plot it land for the highest bidder. As for tax, well that is after depreciation and the depreciation will wipe out taxable profit for a long time. But that results in a massive black hole for the revenue of many countries eg Nigeria, libya, venuzela, the middle east and USA.

Realist,
The project that I linked to alone has received over $1 Billion in subsidies and has not delivered a single watt. It is unlikely to ever generate any power. Nuclear in Florida received much more in subsidies on any basis than renewables. This is a concrete example of nuclear power that is not economic at any price. In Texas they are building a lot of wind. I doubt Texas is subsidizing wind.

If you want to argue that renewables are subsidized more than renewables you must give a concrete example against the one I have produced. Hand waving and saying "probably in Florida too." is not an argument.

Its difficult to find an electricity project that isnt subsidised somehow. $1BN for the nuclear plant. Lets Google Florida...

Ahh Florida electricity is about 10 cents per kwh. Wow thats about the cheapest in the world. For a comparison, Germany is 23 cents per kwh, partially because of all the solar, and Austrialia is 21 cents.

No wonder no company wants to build an electricity plant in Florida without huge subsidies. The alternative is to allow shortages of electricity to push up the price of electricity until it is viable to build a power plant without subsidies.

As for if Texas gets wind subsidies, you betcha! A very quick Google search found the following. Note $1.3BN from 2009 to 2010, unlike the one-off $1BN for your nuclear plant, the wind guys in Texas want this level of subsidy every year...

"The wind industry says it's mobilized to lobby Congress to extend a key subsidy that kept the business going during the recession. Despite having White House support, the program was left out of an agreement announced this week that would extend the Bush tax cuts, unemployment insurance, and a host of other incentives. It has sent more than $1.3 billion to wind-energy projects in Texas since 2009."

As for the subsidy for wind being higher than FF, and you mentioned Texas...

http://www.texaspolicy.com/pdf/2011-WindEnergy-CEF-CEE.pdf

"Subsidies for wind are one source of these costs. Although most energy sources receive some government subsidies, the subsidies for renewable energy sources are far higher on a per unit of production basis than traditional sources of energy.
At $23.37 per MW hour, wind receives 100 times the federal money that natural gas generation receives. The federal government provides hundreds of billions for renewable energy projects, including grants for 35 percent of construction cost."

Re: subsidies. One measurement of subsidies is how much the taxpayer pays versus how much the ratepayer pays. The Texas taxpayer pay very little in subsidies for wind power, and ratepayers pay a very low 11-12 cents per kWh for all sources. Part of the reason is that Texas wind picks up some Federal subsidies. It is all detailed in this report: http://www.window.state.tx.us/specialrpt/energy/subsidies/

Realist:
"The federal government provides hundreds of billions for renewable energy projects," This is obviously a false statement. The federal government does not provide hundreds of billions of dollars for all renewables combined. Provide a reliable source for this absurd claim. Please provide data from a peer reviewed source, not a right wing think tank.

Find a single renewable project that has received $1 billion dollars of subsidy. I have provided an example of such a nuclear facility. They have received $1 billion dollars of subsidy and it has not even started construction yet! You cite right wing propaganda against my specific example.

Realist:
Your citation for the supposed $1.3BN for wind does not list how the money is paid out. As I recall, those are production tax credits. The coal and oil industries get massive tax credits that you have not mentioned. Citing incomplete, right wing propaganda in newspapers does not make a believable argument.

Provide a specific example against my $1Bn nuclear example. The nuclear plant has not yet started construction.

Michael sweet
If you have an interest in the breakdown of subsidies, I suggest you do your own research. Note that you have not given a breakdown of the massive coal subsidies you mention but expect others to provide breakdowns for you. Now is that fair? However I suggest you start with the excellent link by Eric @43, it's very informative.

Realist,
According to Eric's link (the state of Texas), coal is subsidized at 6.9%, nuclear at 21%, wind at 12% and solar at 12%. Since coal and nuclear are mature industries that should receive no subsidies. It is clear that wind and solar are doing well for new industries and their government subsidies are reasonable. This reference states less than 1Bn subsidies total in the US for both wind and solar. They do not count the Florida subsidy of nuclear, because it is paid by the customers and not the government. I imagine that Texas would exaggerate the subsidy of wind and solar and underestimate fossil fuel subsidies.

The fact is that investors will not build nuclear because it is not economic. They are not building coal because there is not enough coal supply to provide coal for the length of the life of a new coal powered generator. Wind and solar are dropping rapidly in price even without much government support. Your claim of "hundreds of billions" of subsidies is so much crap, as are your right wing references. Provide some real data to support your wild claims.

Your post was that the florida nuclear plant was subsidized and you believed it shouldnt be.
My point was that virtually all electricity is subsidized so that the electricity cost to consumers is kept down.
Your point was that you didnt think wind in Texas would be subsidized.
I came back with an article that the wind industry in Texas wants the $1bn in a year subsidy to continue.
You have now read the link by Eric and quoted the subsidies for the different forms of energy. I take that as you acknowledge the subsidies for electricity are widespread and across the different forms of electricity production.

I am not clear what your point is. Can you please be concise as to what it is?

Realist,
My point, as I stated in my first post, was that nuclear power appears to be uneconomic. You have not produced any useful references. Eric's post states that the entire wind industry in the USA receives less than 500 million per year. Your claim of 1Bn/yr for Texas alone is false (as was your claim of "hundreds of billions"). I cited a single nuclear plant that has received over 1Bn in subsidies (over several years). It is not clear what your point is.

Renewables receive less subsidies than established power industries in the USA, which is backwards from what should happen. The OP in this thread discusses whether renewables can produce baseload power. You have produced nothing to support your apparent claim that renewables will not be able to handle all power needs in the future.